Method and apparatus for drilling an underwater well



Aug. 10, 1965 METHOD AND R. A. MALOTT ETAL 3,199,613

APPARATUS FOR DRILLING AN UNDERWATER WELL Filed Sept. 28, 1962 4Sheets-Sheet l FIG. I FIG. 2

INVENTORS:

R. A. MALOTT G. D. JOHNSON THEIR AGENT 1965 R. A. MALOTT ETAL 3,199,613

METHOD AND APPARATUS FOR DRILLING AN UNDERWATER WELL Filed Sept. 28,1962 4 Sheets-Sheet 2 INVENTORS:

R. A. MA LOTT G. D. JOHNS ON M H-i cwz THEIR AGENT Aug. 10, 1965 MALOTTETAL 3,199,613

METHOD AND APPARATUS FOR DRILLING AN UNDERWATER WELL Filed Sept. 28,1962 4 Sheets-Sheet 3 3 r- I I} r :F

-47 37 o O O O 3 Q 0 o O "30 39 I 4-35 Q I 57? 5'65 gfl64 56 6 so 1? 34I J 53 FIG. 9 5| INVENTORSI T FIG. 7 R A MALO T G. D. JOHNSON THEIRAGENT 1965 R. A. MALOTT ETAL 3,199,613

METHOD AND APPARATUS FOR DRILLING AN UNDERWATER WELL 28, 1962 4Sheets-Sheet 4 Filed Sept.

T w T 0 m Q I I M H I. MI: M m u 'm G ll F m A D w T R G Q N E V N I Y BH M M 2 Q V 4 2 a Q $QI I 4T A... V VAk A/K B M .10. NA

THEIR AGENT FIG. I2

United States Patent 3,199,d13 P/iETl-lfil) AND APPARATUS FGR DRl-LLINGAN UNDERWATER WELL Raymond A. Malott, Fullerton, and Glenn D. Johnson,Downey, Calif., assignors to Shell Gil tlompany, New York, N.Y., acorporation of Delaware Filed Sept. 23, 1952, Ser. No. 226,797 Qlaims.(til. 175-5) This invention relates to underwater drilling of oil andgas wells and pertains more particularly to methods and apparatus forre-establishing contact with an underwater well after changing a bitduring drilling operations or :hen installing in the well a conductor,foundation pipe, or other large-diameter well casing.

During recent years, the continued search for oil has resulted indeveloping methods and apparatus for drilling underwater wells atlocations where the water may range from 100 to 1500 feet or more indepth. In these locations it is customary to position the wellhead at aconsiderable distance below the surface of the water, preferably on theocean floor, so that it is not a hazard to the navigation of ships inthe area. One method of drilling and completing wells underwater in thismanner is described in copending patent application, Serial No. 830,538,filed July 30, 1959, and entitled Underwater Well Completion Method.

One of the most important operations in the drilling of an underwaterwell is that of starting the well and installing the conductor orfoundation pipe in th ocean floor. This operation may be carried out inany one of several ways, two of which are described in US. Patent2,929,610 which issued March 20, 1966 to H. Stratton, and US. 2,891,770which issued June 23, 1959 to R. P. Bauer et al. In one method a drillbit drills a hole in the ocean floor slightly larger in diameter thanthe diameter of the well conductor or foundation pipe which issubsequently slipped down along the drill pipe and into the hole duringwhich time drilling fluid is pumped down the drill pipe and up theoutside of the foundation pipe. In another method, a hole is flushed inthe ocean floor for the well conductor or foundation pipe by pumpingfluid down through the conductor, allowing it to jet out the lower endthereof to wash a hole in the ocean floor into which the conductor pipeis progressively lowered. The conductor pipe is then held in the holeuntil the surrounding earth has had time to settle in around the outsideof the pipe and anchored firmly in the hole. In certain locations, theabove-described methods of starting to drill a well in the ocean floorand posi' tioning a well conductor or foundation pipe therein areunsatisfactory because of the soil conditions of the ocean floor or thedrilling conditions in general. In some areas it is necessary to changea drill bit prior to installing the well conductor or foundation pipe.In employing one of the presently known methods or starting a well inthe ocean floor, it is impossible to change a bit at the end of thedrill string since contact would be lost with the hole in the oceanfloor when the drill string and is bit were withdrawn to the vessel atthe surface of the ocean in order to change the bit. Contact between thevessel and the hole in the ocean floor would also be lost in the eventthat it was necessary to withdraw the drill string from the hole duringa severe storm.

It is therefore a primary object of the present invention to provide amethod for establishing contact between a vessel floating on the surfaceof the ocean and a hole or well in the ocean floor.

A further object of the present invention is to provide a method andapparatus for starting the drilling of an underwater well with the drillbit and subsequently chang- 3,19%,613 Fatented Aug. 10, 1965 ing thedrill bit to a new one of the same size or one of another size withoutlosing contact between the hole and the ocean floor and the vessel onthe surface of the ocean.

Another object of the present invention is to provide apparatus forguiding well drilling equipment or tubular members from a vessel on thesurface of the body of water to a well or a well foundation pipe sunk inthe ocean floor so that well drilling operations may be continued afterthe original hole has been drilled or after the foundation pipe has beeninstalled therein.

It is a further object of the present invention to provide a method andapparatus for guiding the lower end of a pipe string suspended from thevessel into contact with an underwater wellhead for work-overoperations.

These and other objects of this invent-ion will be understood from thefollowing description taken with reference to the drawing, wherein:

FIGURES 1 through 4 are diagrammatic views taken in longitudinalprojection illustrating a floating vessel positioned over a drillinglocation during the sequential steps of starting a well, withdrawing thedrill string back to the vessel, lowering a pipe string from the vesselto a point adjacent the ocean floor, and reestablishing contact betweenthe vessel and the well in the ocean floor by 10- cating the well andinserting at least the lower end of the pipe string in the well.

FlGURE 5 is a diagrammatic view taken in longitudinal cross sectionillustrating the lowering of an auxiliary drill bit into the lower endof a pipe string or drill string;

FIGURE 6 is a diagrammatic view taken in longitudinal projectionillustrating a floating vessel positioned at a drilling location with apipe string depending from the vessel and establishing contact with anunderwater wellhead.

FIGURE 7 is a view taken partially in longitudinal cross sectionillustrating a television camera observation unit positioned in thelower end of a drill string and extending through an opening in the bitthereof;

FIGURE 3 is a cross sectional view taken along the line 88 of FIGURE 7;

FIGURE 9 is a view taken in partial longitudinal cross sectionillustrating the lower end of the drill string of FIGURE 7 with theaxial opening through the bit being provided with an auxiliary or pilotbit;

FIGURE 10 is a longitudinal view taken partially in cross section of thelower end of a pipe string illustrated as being provided with a valvedjet port through the side wall thereof and means for orienting anobservation unit in the bore thereof;

FIGURE 11 is a longitudinal view taken partially in cross section of thepipe string of FIGURE 9 with an observation unit positioned therein andlatched to a fishing tool; and

FlGURE 12 is a diagrammatic view taken in longitudinal projection ofanother form of well-locating apparatus.

Referring to FIGURE 1 of the drawing, the drilling vessel, barge orplatform 11, of any suitable floating or floatable type, is illustratedas floating on the surface of a body of water 12 while beingsubstantially fixedly positioned over a preselected well location bysuitable vessel-positioning means well known to the art, or by beinganchored to the ocean floor 13 by anchor lines 14 and 15 running toanchors (not shown). Equipment of this type may be used when carrying onwell-drilling operations or well work-over operations in watervaryingfrom about feet to 1500 feet or more in depth. The drilling vessel 11 isequipped with a suitable derrick 16 containing a fall line system 17which'includes a suitable hoist 18, traveling block 19, and suitablehook and swivel or other connector means 20 adapted to be connected tothe top of a drill pipe 21 during well drilling operations and beingadapted to circulate a drilling fluid therethrough in a manner wellknown to the art. The vessel 11 is also provided with other auxiliaryequipment needed during well drilling operations, such for example as arotary table 22 positioned on the operating deck, a hinged slip andspider assembly, etc. The derrick 16 is positioned over a drilling slotor well 23 which extends vertically through the barge in a conventionalmanner. When using equipment of the present invention, a slot 23 in thevessel 11 may be either centrally located or extend in from one edge.Alternatively, drilling operations may be carried out over the side ofthe vessel without the use of a slot. For example, the drilling vesselmay be provided with a deck portion which overhangs the hull of thevessel.

In drilling a well in accordance with the method of the presentinvention while using the apparatus described, a drilling vessel ispositioned at a selected offshore location and a drill string includinga bit secured to the lower end thereof is lowered from the vessel intocontact with the formation beneath the body of water. A hole or well isformed in the formation, as by drilling, while advancing the drillstring thereinto. After the hole has been drilled to a desired depth,the drill string is withdrawn from the hole and back to the vessel. Apipe string having an axial opening in the lower end thereof is thenmade up at the vessel and lowered from the vessel to a position near theformation beneath the body of water. A well-locating device preferablyin the form of an observation unit, for example a television camera, islowered through the pipe string to the lower end thereof so that it isin register with the opening in the lower end. The pipe string, or atleast its lower end together with the television camera is movedsubstantially laterally relative to the formation to locate the top ofthe hole drilled in the formation so that the lower end of the pipestring can be positioned in register thereabove. Alternatively, if thelower end of the pipe string is close to the hole or well in theformation when it is originally lowered, it may be sufi'icient merely torotate an element of or the entire camera means at the end of the pipeor the pipe itself in order to find the hole. After locating the hole,at least the lower end of the pipe is positioned in the hole after whichthe television camera is withdrawn back to the vessel. The pipe stringextending between the vessel and the ocean floor is used as a guidestring along which a foundation pipe or well casing may be guided into awell. If further drilling is to be continued, a drill bit may be loweredthrough the pipe string to convert the pipe string to a drill string. Insuch a case the drill bit would be either an auxilary or a core-type bitwhich would replace the observation unit in the bottom of the pipestring.

The drill string 21 (FIGURE 1) preferably includes a conventionaltelescoping joint 24 in its length to compensate for the rise and fallof the vessel 11 relative to the drill string 21. The drill string 21also includes a drill bit 25 at its lower end which is provided with anaxial vertical opening26 (FIGURE 5) therethrough in which a pilot bit 27or a core bit and core barrel (not shown) may be latched in a suitablemanner well known to the art. As shown in FIGURE 9, the auxiliary bit 27is in the form of a removable rock bit having cutting cones 28 and fluidcirculation ports 29. The drilling assembly of FIGURE 9 includes a bithousing or sub 30 threadedly secured to the lower end of the drillstring 21. The lower end of the housing or sub 30 is provided with acutter head 31 having a plurality of cutter elements 32 rotatablymounted thereon. The inner surface of the housing or sub 30 is providedwith latching recesses 33 and a shoulder 34 on which the body 35 of theauxiliary bit 27 is adapted to be seated. The auxiliary bit body 35 isprovided with spring-loaded outwardly-extendible latches or dogs 36adapted to latch in recesses 33 on the inner wall of the sub 39. Thelatches 36 are connected, as by linkage members 37, to a stem 38 whichis normally urged downwardly by a spring 39 so that the latches 3d areurged outwardly. The top of the stem 38 is in the form of a fishing head40 adapted to be engaged by any suitable type of fishing tool 41 (FIGURE5) for Withdrawing the bit from the lower end of the pipe string ordrill string 21 or for inserting it into the lower end thereof.

In originally drilling the first portion of the well or hole 42(FIGURE 1) in the ocean floor, the drill bit 25 may be of any type andnot one that necessarily has a removable auxiliary bit secured to it.After drilling the hole 42 to the desired depth as shown in FIGURE 1,the drill string 21 and the bit 25 is removed from the hole (FIGURE 2)and withdrawn to the vessel. This operation takes place in the eventthat the drill bit 25 has become dull and must be changed or in theevent that it is desired to lower a Well conductor or foundation pipeinto the hole 42 in the ocean floor before proceeding with furtherdrilling.

In the event that further drilling of the hole 42 is to be carried out,a pipe string 43 (FIGURE 3) is made up at the vessel 11 which may besimilar or identical to the drill string 21 with the exception that,instead of having any type of bit 25 attached to the lower end thereof,a bit housing or sub 36 would be secured thereto. In well operations itis well known that a pipe string or drill string is made up bythreadedly connecting together several short (say, 30 feet) sections ofpipe together to make a pipe string of the desired length. Several ofthe bottom sections of pipe may be thick-walled pipe in the form ofdrill collars, if desired. With the lower end of the pipe string 43positioned near the ocean floor 13, as illustrated in FIGURE 3, awell-detacting device in the form of a television camera, for example,is dropped through the pipe string or lowered therethrough on a cable.

The television camera represented in FIGURE 3 by numeral 44-, is shownin greater detail in FIGURE 7. One form of the television well-findingassembly comprises a body member 45 having outwardly-extending latches46, linkage members 47 and a spring-loaded stem 48 similar to elements36, 27 and 38 on the removable drill bit body 45 of FIGURE 9. Thus, anupward pull on the cable 5-9 secured to the top of the stem 48 willcause the latches 46 to be retracted from the recesses 33 in the sub 3%so that the television assembly can be withdrawn from its seatedposition on shoulder 34.

In order to allow use of the apparatus of the present invention in pipestrings of relatively small diameter, the body of the televisionassembly is provided with a television camera 59 which is preferablyarranged in a vertical or downwardly-directed position above avertically-directed recess 51 in the lower end of the body member 45.The lower end of the body member 45 may be tapered, as at 52, tofacilitate entry of the apparatus in a well or in the top of a pipealready positioned in the well. Although the downwardly-directedtelevision camera may be used satisfactorily to find a hole or wellbored in the ocean floor, the well-finding apparatus of the presentinvention is made more versatile by the mounting of a mirror 53 belowthe television camera 5%. The mirror 53 is preferably mounted formovement in a vertical plant about a horizontal axis by pivot pin 54.The position of the pivot pin 54 and of the mirror 53 attached theretomay be selectively changed by any suitable remotely-controlled operator,such for example as a Selsyn motor 55 (FIGURE 8) carried by the bodymember 45. A control cable 56 from the Selsyn 55 extends through thebody member 45 and may be connected to the leads or control cable 57which is adapted to transmit current to and signals from the televisionscamera 50. The cable 57 in turn passes 29 through an enlarged portion ofthe stem 43 as a weight bar 58 and then upwardly to a point where itforms part of the cable 49 which is preferably both a load-supportingand signal and current-transmitting cable.

In order to illuminate the area below the elevision camera the bodymember 55 is provided with suitable light means, such for example as adownwardly-directed iiood light 59 having a current lead 60.Additionally, the downwardly-extending portion of the body member 45 maybe provided with the one or more annular or helically-shaped lightsources 61 which are positioned in a recess 62 in the outer wall of thebody member 45. The back of the recess 51 in the lower portion of thebody member 45 is shaped in a manner such that the mirror 53 fits flushagainst it when in a vertical position, thus giving an unobstructed viewfrom the television camera 59 in a vertical direction. The use of avariable angle mirror 53 is more advantageous in locating a structuresuch as a wellhead positioned above the ocean floor than in locatingmerely a hole in the ocean floor.

To facilitate movement of the lower end of a depending pipe string, thelower end of the pipe string is provided with an outwardly-directedunidirectional port through which fluid may be discharged. As shown inFIGURE 7 this port 63 may be contained in the television assembly bodymember 45. It is preferably directed in a direction opposite to that inwhich the mirror 53 is looking when the mirror is used. The upper end ofthe port 63 is in communication through chamber 64 and flow passage 65with the interior 66 of the pipe string 43. Thus, fluid being pumpeddown under pressure through the pipe strin 43 will be jetted out throughthe port 63 causing the lower end of the pipe string 43 to movelaterally through the water, as shown in FIGURE 3, until it has assumeda position in register with the hole 42. After the pipe string 43(FIGURE 3) ,is in register with the top of hole 42 in the ocean floor13, it is moved downwardly into the hole until at least the lower end ofthe pipe string is in the hole 4-2. When the lower end of the pipestring 43 has assumed this position, as shown in FIGURE 4, thetelevision assembly in withdrawn out of the pipe string by an upwardpull on the cable 49 (FIGURE '7). After the television assembly has beenwithdrawn from the bottom of the pipe string, an auxiliary bit 27(FIGURE 5) may be 1 wered on a wire line 65 into position at the bottomof the drill string. In soft formations the drilling operations may becarried out without the use of the auxiliary bit 2? bein; positioned inplace. Gne suitable type of drill bit for use with the present inventionis a Reed Roller Bit Company BR wire-line retractible core cutter anddrill bit assembly illustrated on pages 423-74 of the 1962-63 CompositeCatalog of Oil Field Equipment and Services.

When the pipe string 43 is positioned in the hole 42 in the ocean floori3 as shown in FIGURE 4, with the television assembly withdrawn from thelower end of the pipe string, the pipe string may be used as a guidealong which a well conductor or foundation pipe 5'7 (FIGURE '6) may belowered and guided into the hole 42 where it may be cemented, ifdesired. As shown in FIGURE 6 the well conductor or foundation pipe 67is provided with a funnel-shaped top 63 and a base plate 59 adapted torest on the ocean floor 13. To re-estaolish a connection between thevessel 11 on the surface or" the water 12 and the foundation pipe 67,the upper end of the pipe string 4-3 is suspended from the vessel eitherfrom the rotary table 22 or a connector unit 213 such as a power swivelwhich is well known to the art. Whatever the manner of suspension of thepipe, the upper end of the pipe 43 is connected by a hose "ill to asuit-able pump '71, such as a mud pump positioned on the vessel 11. Ifthe vessel 11 is not directly over the foundation pipe 67 one method ofmoving the lower end of the pi e string 43 is to start pumping fluiddown the pipe 4-3 and out the horizontally disposed port 63 in the lowerend thereof so that it is jetted substantially horizontally, as at 72.The jet action will cause the lower end of pipe 43 to bend away from itsnormally vertical suspended position since an elongated pipe, say 300feet long, of small diameter is relatively flexible. The lateraldistance that the lower end of the pipe 43 moves can be varied byvarying the pump pressure at the vessel. At the same time the upper endof the pipe can be slowly rotated from the vessel, as by securing it inthe rotary table 22 and slowly moving the rotary table until thetelevision assembly 44 in the lower end of the pipe string 43 has had achance to scan a circular area of the ocean floor beneath the vessel 11.In the event that the foundation pipe 67 (FIGURE 6) is not found on thefirst circle scanned by the television assembly 4 the pump pressure canbe increased .to increase the jetting action at 72 causing the lower endof the pipe to be deflected a greater distance from its verticalposition so that when it is rotated at the top the television assemblywill sweep a larger concentric area than the previous area scanned. Inthis manner the well or well head is located.

In the event that the pipe string 43 was to be used only to act as aguide to insert a foundation pipe in the ocean iioor, it may not ofnecessity be provided with the bit housing or sub 3 -1). Instead thelower end of the drill pipe 43 could be in the form shown in FIGURES l0and 11 of the drawing. Thus, in FIGURE 10 the lower end of the pipestring 4-3 is shown as being provided with a port 73 in the side wallthereof that is horizontally directed. It is normally closed by a sleevevalve '74 normally held in an upward position by compression spring 75.The lower end of the pi e 43 may be provided with a suitable aligningmeans which may be in the form of a short pipe section 76 having asloping shoulder 77 tapering from a point at one side down to anorienting notch 78 at the bottom. Thus, in dropping a television orother assembly down through the pipe string 43 or lowering it by meansof a fishing head 41 as shown in FIGURE 10, an outwardly extending lugor pin 79 on the outer surface of the television body member 86 willcontact the shoulder 77 at any point and slide down along the shoul derinto notch 78 to the positionillustrated in FIGURE 11. The orientingmeans with the aligning notch 73 is employed in the event that it isdesired to position the tiltable mirror 5'3 of the television assemblyso that it is aimed in the opposite direction from the jet port 73 inthe wall of the pipe string 43. When the television unit 84 of FIGURE 11is seated in place, a flange 81 rests on top of valve 74 pressing itdownwardly to compress spring '75 and open port 73 so that fiuid beingpumped down pipe string 43 will be discharged and jetted out the port'73.

While the method of the present invention has been descr bed with regardto using television apparatus for 10- eating a well or hole in the oceanfioor, it is to be understood that other well locating devices wellknown to the art could also be used. Thus, after drilling a well to adesired depth and removing the auxiliary bit 27 i from the end of thedrill string or pipe string 4-3 as shown in FIGURE 5, any suitablewell-marking device could be dropped down through the pipe string 43 andout the lower end thereof and into the borehole &2. As showndiagrammatically in FIGURE 12, a seismic energy generating source 82,known as a transponder, could be dropped through the pipe string 43being pulled therethrough by a weight 83 which would rest on the bottomof the borehole 42 and be connected to thetransponder 82 by an anchorline 34 substantially equal to the depth of the well. With thetransponder in a buoyant container it would be positioned over the mouthof the well.

In locating an .underwaterwell having a transponder 82 .1 positioned insuch a manner, the television assemblyC (FIGURE 10) would be replacedbya suitable logging instrument well known to, the art having a'transmitter and receiver unit. The transmitter unit may be in the formof a spark gap adapted to emit a seismic signal while the receiver wouldbe any suitable type of pressure detector, hydrophone, crystal detector,etc. The transmitter and receiver would be connected by means of a cablesimilar to 49 (FIGURE 7) running up to the vessel.

- When a seismic impulse is transmitted by the transmitter 83 it ispicked up by the receiver 84 and by the transponder 82 triggering thetransponder to put out a similar seismic signal. The time intervalbetween the signals coming from the transponder 82 and the transmitter83 are measured and the pipe string 43 is moved in any suitable mannerto a new position. Movement of the pipe 43 is continued until the timedelay between the signals received from the transponder 82 and thetransmitter 33 reaches Zero at which time the lower end of the pipe 43is over the transponder 82 in the mouth of the well 42. The pipe 43 canthen be lowered into the well. When drilling operations were resumed thetransponder 82 and its anchor 83 would be ground up by the bit. Thetransmitter 83 and the receiver 84 would be mounted on the body membersimilar to element 8% in FIG- URE 10.

The electrical leads carried by the weight-supporting and signal andcurrent-transmitting cable 49 (FIGURE 7) are connected at the surface toa suitable indicating device, recorder, viewing screen, etc. 85,depending upon the type of well-findin g unit being employed in thelower end of the pipe string to locate the well. While the televisionassembly of FIGURE 7 has been described with regard to having a mirror53 mounted on a horizontal axis below the television camera 50, it is tobe understood that the television well-finding assembly may be usedwithout the mirror. Additionally, a wider range of vision for thetelevision camera 50 may be obtained by cutting away the body member 45below the television camera t Also, instead of mounting the mirror 53 ina horizontal pivot, a mirror placed at a fixed angle, say 30 degreesfrom the vertical, may be positioned below the television camera androtated on a vertical axis to scan the ocean floor to the side of thelower end of the pipe.

We claim as our invention:

1. A method of locating and establishing contact with an underwater wellfrom a vessel on the surface of a bod of water, said method comprising 1(a) positioning a drilling vessel at a selected offshore location (b)making up at the vessel a pipe string having an axial opening in thelower end thereof,

(c) lowering the lower end of said pipe string from said vessel to aposition near the ocean floor beneath said body of water,

(d) lowering down through said pipe string and positioning in the lowerend of said pipe string well finding means operatively connected toindicating means on said vessel (e) moving said pipe string and saidwell finding means means to scan the ocean floor and locate the top ofthe well drilled in said ocean floor and to position the lower end ofthe pipe string in register thereabove, and

- (f) lowering said pipe string until at least the lower end thereof isin the Well.

2. A method of locating establishing contact with an underwater wellfrom a vessel on the surface of a body of Water, said method comprising(a) positioning a drilling vessel at a selected offshore location (b)making up at the vessel a pipe string having an axial opening in thelower end thereof,

(0) lowering the lower end of said pipe string from he ocean floorbeneath (d) lowering through said pipe string and a register with theopening in the lower end thereof television camera means operativelyconnected to viewing ,means on said vessel,

(e) moving said pipe string and said camera means to scan the oceanfloor while observing said viewing means on said vessel to locate thetop of the well drilled in said ocean floor and position the lower endof the pipe string in register thereabove,

(f) lOWeTing said pipe string until at least the lower end thereof is inthe well, and

(g) withdrawing said camera means back to the vessel.

3. A method of drilling an underwater well from a vessel on the surfaceof a body of water, said method comprising (a) positioning a drillingvessel at a selected offshore location (b) lowering from said vesselinto contact with the ocean floor beneath the body of water the lowerend of a drill string including a bit secured to the lower open endthereof,

(c) forming a hole in said ocean floor while advancing said drill stringthereinto,

(d) Withdrawing said drill string to said vessel,

(e) making up at the vessel a pipe string having an axial opening in thelower end thereof,

(f) lowering said pipe string from said vessel to a position near theocean floor beneath said body of water,

(g) lowering through said pipe string and in register with the openingin the lower end thereof television camera means operatively connectedto viewing means on said vessel,

(h) moving said pipe string and said camera means to scan the oceanfloor to locate the top of the hole drilled in said ocean floor andposition the lower end of the pipe string in register thereabove,

(i) lowering said pipe string until at least the lower end thereof is inthe hole, and

(j) withdrawing said camera means back to the vessel.

4. The method of claim 3 including the steps of (k) subsequentlylowering a drill bit through said pipe string and partially out theopening in the lower end thereof,

(1) securing said drill bit to the lower end of the pipe string, and

(m) continuing drilling of the hole in the ocean floor.

5. The method of claim 1 wherein the pipe moving step includes the stepof moving at least the lower end of said pipe string together with saidwell-finding means to scan the surface of the underwater ocean floor tolocate the hole drilled therein.

6. The method of claim 5 wherein said pipe string is rotated from theupper end thereof.

7. The method of claim 5 wherein the lower end of the pipe string isdisplaced laterally from a normally vertical depending position.

8. The method of claim 7 including the step of at least partiallyrotating the upper end of said pipe string to cause the lower endthereof to move through an arc.

9. The method of claim 7 including the steps of pumping a fluid underpressure from said vessel down said pipe string and discharging saidfluid laterally from the lower end of said pipe string in one direction.

10. Apparatus for locating and establishing contact between a vessel onthe surface of the ocean and a hole in the ocean floor, said apparatuscomprising a pipe string depending from said vessel with the lower endof the pipe string near the ocean floor,

means on said vessel for suspending said pipe string near its upper end,

television mean carried at least partially within said pipe string atthe lower end thereof and television receiving means carried on saidvessel for viewing the area around thelower end of thepipe string,

1 acabl-extending from said'television means upwardly through said pipestring to the television receiving means on the vessel at the surface,and means for moving said pipe string relative to said ocean.

11. The apparatus of claim 10 including latch means for latching saidtelevision means within said lower end of said pipe string, one portionof said latch means being carried by the inner Wall of said pipe stringand a cooperating portion of said latch means being carried outwardly bysaid television means.

12. The apparatus of claim 11 wherein one portion of said latch meanscomprises latching recess means in the inner Wall of said pipe stringand the other portion of said latch means comprises radially extensiblelatch elements of a size to engage said latching recess means.

13. The apparatus of claim 10 including means closing of the lower endof said pipe string and a substantially laterally-directed fluiddischarge port carried near the lower end of said pipe string and incommunication with the bore thereof whereby fluid pumped down said pipeas string may be jetted therefrom.

M. The apparatus of claim 13 including pump means carried on the vesseland connected to the upper end of said pipe string for pumping fluidtherethrough.

15. The apparatus of claim 14 including pipe rotating means carried bysaid vessel and operatively engaging said depending pipe string forrotating said pipe string.

References Cited by the Examiner UNITED STATES PATENTS CHARLES E.OCONNELL, Primary Examiner.

BENJAMIN HERSH, Examiner.

1. A METHOD OF LOCATING AND ESTABLISHING CONTACT WITH AN UNDERWATER WELLFROM A VESSEL ON THE SURFACE OF A BODY OF WATER, SAID METHOD COMPRISING(A) POSITIONING A DRILLING VESSEL AT A SELECTED OFFSHORE LOCATION (B)MAKING UP AT THE VESSEL A PIPE STRING HAVING AN AXIAL OPENING IN THELOWER END THEREOF, (C) LOWERING THE LOWER END OF SAID PIPE STRING FROMSAID VESSEL TO A POSITION NEAR THE OCEAN FLOOR BENEATH SAID BODY OFWATER, (D) LOWERING DOWN THROUGH SAID PIPE STRING AND POSITIONING IN THELOWER END OF SAID PIPE STRING WELL FINDING MEANS OPERATIVELY CONNECTEDTO INDICATING MEANS ON SAID VESSEL (E) MOVING SAID PIPE STRING AND SAIDWELL FINDING MEANS MENS TO SCAN THE OCEAN FLOOR AND LOCATE THE TOP OFTHE WELL DRILLED IN SAID OCEAN FLOOR AND TO POSITION THE LOWER END OFTHE PIPE STRING IN REGISTER THEREABOVE, AND (F) LOWERING SAID PIPESTRING UNTIL AT LEAST THE LOWER END THEREOF IS IN THE WELL. 10.APPARATUS FOR LOCATING AND ESTABLISHING CONTACT BETWEEN A VESSEL ON THESURFACE OF THE OCEAN AND A HOLE IN THE OCEAN FLOOR, SAID APPARATUSCOMPRISING A PIPE STRING DEPENDING FROM SAID VESSEL WITH THE LOWER ENDOF THE PIPE STRING NEAR THE OCEAN FLOOR, MEANS ON SAID VESSEL FORSUEPENDING SAID PIPE STRING NEAR ITS UPPER END, TELEVISION MEAN CARRIEDAT LEAST PARTIALLY WITHIN SAID PIPE STRING AT THE LOWER END THEREOF ANDTELEVISION RECEIVING MEANS CARRIED ON SAID VESSEL FOR VIEWING THE AREAAROUND THE LOWER END OF THE PIPE STRING, A CABLE EXTENDING FROM SAIDTELEVISION MEANS UPWARDLY THROUGH SAID PIPE STRING TO THE TELEVISIONRECEIVING MEANS ON THE VESSEL AT THE SURFACE, AND MEANS FOR MOVING SAIDPIPE STRING RELATIVE TO SAID OCEAN.